In the field of construction of buildings, such as residences, commercial buildings, etc., it is well known that securing windows and doors requires great care to make sure the windows or doors are installed to be level, plumb and square. The windows or doors must be secured within an opening defined by a frame of the building so that there is a gap between an exterior frame of the window or door and an opening frame of the building. The gap surrounding the window or door must define a sufficient distance between structural surfaces of the frames so that any shifting loads of the opening frame of the building do not compress or re-align the exterior frame of the window or door against the opening frame of the building. By maintaining a gap between the exterior frame of the window or door and the opening frame of the building, loads that are generated by slight movements in the building frame are transferred around the window or door by way of the gap and do not pass through the window or door. If there were no such gap, it is well known that a shifting load could compress the opening frame of the building against the exterior frame of the window or door to make it extremely difficult to properly operate the window or door, and such a shifting load may also misalign the window or door.
It is likewise well known that shims are placed between the exterior frame of an insertable structure such as window or door and the opening frame of the building. Typically, the shims are used in pairs wherein each shim has a thick back end and a thin front end, a flat base surface and an opposed sloped contact surface extending between the ends. It is common that the gap distance between structural surfaces of the frames is more than one-quarter inch and less than one-half inch. Historically, shims have been inexpensive wedge-shaped components made of wood, and many carpenters prefer that the wood be cedar. A classic wooden shim is about six to ten inches long, has about a one-sixteenth inch thin front end and about a three-eighths inch thick back end, and is about one and a quarter inches wide.
An exemplary procedure for utilizing shims to adjust distances between an exterior frame of an insertable structure and an opening frame of a building is as follows. First, to make sure the insertable structure will be level, at least two pairs of shims are placed on a sill (being a portion of the opening frame that defines a bottom of the opening frame and is generally parallel to a reference surface, such as the surface of the earth). A carpenter places a level across both pairs of shims on the sill, and the thick ends of the shims of one or both pairs are moved toward or away from each other to increase or decrease a distance between the base surfaces of the adjacent shims until the level indicates that a plane across the pairs of shims is parallel to the ground (or any other reference surface to which it is desired that the sill be parallel). The pairs of shims are then secured to the sill at the desired thicknesses.
Next, the carpenter rests the insertable structure or window, door, etc. upon the pairs of fixed shims on the sill, which results in the structure being level. In a similar manner, pairs of shims are secured between the opposed vertical sides of the exterior frame of the structure and the opening frame, as well as between a top of the exterior frame and the opening frame. Typically the pairs of shims are inserted from opposing sides of the insertable structure and held in place temporarily by friction between side and top structural surfaces of the opening frame of the building and the exterior frame of the window or door. Then the pairs of shims are adjusted incrementally to vary distances between the sides and top of the exterior frame by moving thick ends of the shims toward or away from each other until measuring tools indicate the sides of the structure are plumb and that the entire structure is square (meaning that diagonal distances from opposed top and bottom corners are identical and that the rectangular or square structure has not become a parallelogram). Incremental adjustment of the shim pairs typically requires two hands; one to hold one shim stationary, and another to tap or pull the other shim of the pair. When the shim pairs are adjusted so that the structure is plumb and square, the shims are secured, such as by a nail gun, to a frame structure of the opening frame, or often through the exterior frame of the insertable structure, through the adjusted shim pair, and into the opening frame.
Many efforts have been undertaken to produce more efficient shims and shim pairs. For example, U.S. Pat. No. 6,018,916 that issued on Feb. 1, 2000 to Henry discloses an adjustable, two-part wedge shim spacer that is to be secured to a portion of an opening frame of a prefabricated building. The shim pairs of Henry utilize a parallel central guide channel and channel follower to assist in correct alignment of the wedge shims. More recently, U.S. Pat. No. 7,156,431 that issued on Jan. 6, 2007 to Norgaard shows a wedge couple for adjusting windows and doors. Norgaard utilizes specially formed mounting shears to move a mated wedge couple toward each other to increase a thickness of the wedge couple. The wedge couple includes a deformable thin plate that connects each wedge of a wedge couple together, to facilitate use of the wedge couples. While having the plate keep the shims adjacent each other affords possible installation with only one hand, unfortunately, use of the mounting shears severely limits practical application of the Norgaard wedge couple and requires use of the other hand.
Even more recently, U.S. Pat. No. 8,136,308 that issued on Mar. 20, 2012 to Slott et al. shows a wedge set wherein one of the wedges includes an upwardly protruding rib including jagged-like teeth on opposed sides of the rib. The other wedge includes a corresponding groove to receive the rib and to provide for irreversible or one-way movement as thick ends of the wedges are moved toward each other. While such an arrangement may achieve limited value in varying distances between structural surfaces, nonetheless the wedge set of Slott et al. involves complexities that limit broad application to different types of structural surfaces and that significantly increases manufacturing costs.
While advances have been made in such shims and shim pairs, there is still a need for low-cost, efficient shims or shim pairs that may be efficiently manufactured and that enhance ease of use and accuracy of application of the shims.